Invertable table top support for machines



arch 21, 1967 5. J. BIRGINAL INVERTABLE TABLE TOP SUPPORT FOR MACHINES 4 Sheets$heet 1 Filed Dec.

INVENTOR.

SYLVESTER J. BIRGINAL March 21, 1967 5. J. BIRGINAL 3,310,352

INVERTABLE TABLE TOP SUPPORT FOR MACHINES Filed Dec. 22, 1964 4 Sheets-Sheet 2 20 INVENTOR. F 56. 4 SYLVESTER J. BIRGINAL arch 21, 1967 5. J. BlRGlNAL 3,310,352

INVERTABLE TABLE TOP SUPPORT FOR MACHINES Filed Dec. 22, 1964 4 Sheets-Sheet 5 0 9 g; i & a N- 53 a El a 2 x W l O 1 Q r o\ i N T 7 v /y 33 Mir Q y W N 1, j! I S d.\ "'I E I v b "L m iji x 11o 1 515' I i-i y 3 g I 2 INVENTOR. SYLVESTER J. BIRGINAL March 21, 1967 s. J. BIRGINAL 3,310,352

INVERTABLE TABLE TOP SUPPORT FOR MACHINES Filed Dec. 22, 1964 4 Sheets-Sheet 4 LENGTH OF SPRING INVENTOR. A 135 SYLVESTER J. BIRGINAL BY H mo w m United States Patent Ofiice 3,310,352 Patented Mar. 21, 1967 3,310,352 KNVERTAELE TABLE TOP SUPPGRT FGR MACHINES Sylvester .l. Birginal, 4609 N. 67th St., Milwaukee, Wis. 53218 Filed Dec. 22, 1964. Set. No. 420,398 Claims. (Cl. 31230) This invention relates to an invertable table-top support for machines and, more particularly, a table-top support for alternatively supporting a machine, such as a sewing machine, in either an upright exposed position or an inverted concealed position.

The primary object of this invention is to provide an invertable machine support in the top of a cabinet, which support has a machine mounting on one side and a plain top surface on the other side, so that when the support with the machine thereon is tilted 180 from its normal operating position, the cabinet has a planar top. The invention constitutes an improvement over the structure disclosed in the patents to Williams No. 2,528,935 and Hohmann No. 2,247,380 in that the subject device provides a spring counterbalance which is intended to achieve the following results: When the invertable support, with a machine mounted on one side thereof, first starts to swing from its full upright position, i.e., the position in which the machine is upright, the spring exerts a slight pulling effect up to about 2230 of movement which helps get the swinging movement of the support started. At about 2230, the machine has tipped off-center enough so that its weight would tend to cause it and its support to start to flip, but at that point the pin to which the free end of the spring is attached starts to swing away from the fixed end of the spring so that the spring starts to stretch and thereby counterbalance the off-center weight of the machine. As the downward component resulting from the off-center weight of the machine increase from about 2230 of tilt to 45 tilt, it approaches the position in which it is counterbalanced by the increasing spring tension. During the next 45 of movement, the counterbalancing forces of the spring increase, but so also does the overbalance of the machine off to one side of the pivot increase so that the spring reaches a point of stretch where it counterbalances the olf-center weight of the machine. Then, for about the next 45 of movement, as the machine swings further downwardly to about of its way towards ful inversion, the length of the spring rapidly increases so that a slight afiirmative manual force must be applied to the support to make it swing around. Then, during the final 45 of movement of the support, the rate of increase in length of the spring rapidly diminishes so that the last few inches of springing movement, as the machine reaches full inversion, require only a small manual force to be exerted upon the support. The foregoing is intended to be accomplished by providing for the anchorage of a counterbalancing coil spring below the pivot for the machine base, the connection of the free end of the coil spring to a post disposed on the base radially outward of the pivot, and the arrangement of the parts so that the post, with the free end of the spring attached thereto, can swing a full 180.

A further object, in conjunction with the foregoing, is to utilize the post to which the free end of the counterbalancing spring is attached, as a stop-engaging member for positively limiting the movement of the machine base to a total of 180, in the 0 position of which the machine-is fully upright, and in the 180 position of which the machine is inverted and a fiat table insert on the bottom of the base is flush with the top of the support.

An additional object, in conjunction with all the above objects, is to provide a hollow pivot through which an electric chord enters from the exterior of the cabinet to the machine base. Also, when the assembly is used for housing a sewing machine head, it is intended to utilize another hollow pivot for accommodating electrical circuit wires leading from the sewing machine to a rheostat mounted on a fixed part of the cabinet.

These and other objects will be apparent from the following specification and drawings, in which:

FIG. 1 is a perspective view of a portable sewing machine cabinet embodying the invention, showing the planar top of the machine support exposed, the sewing machine being housed in the cabinet, and with supporting legs retracted beneath the cabinet;

FIG. 2 is a perspective view showing the machine support inverted 180 from the position of FIG. 1, with the machine in upright position, and with the retractable legs of the cabinet extended;

FIG. 3 is a vertical cross-sectional view of the cabinet along the line 33 of FIG. 2, showing the support in 0 degree position wherein the machine supported thereon is upright;

FIG. 4 is a view similar to FIG. 3, but showing, in full, the support tilted to its 180 position and showing, in broken lines, the support tilted somewhat beyond and also showing the legs retracted;

FIG. 5 is a vertical cross section along the line 5-5 of FIG. 3;

FIG. 6 is a vertical cross section along the line 6-6 of FIG. 5;

FIG. 7 is a fragmentary cross section along the line 7-7 of FIG. 6;

FIG. 8 is a perspective view showing the free end of the spring, the arm to which it is connected, and the stop surfaces on the rail;

FIG. 9 is a diagram showing relative lengths of the spring and position of the approximate center of the weight of the machine throughout the various swing positions of its free end; and,

FIG. 10 is a bar graph showing relative lengths of the spring throughout its various swing positions.

Referring now to the drawings, in which like reference numerals denote similar elements, the invention as shown is embodied in a portable sewing machine cabinet 10. It should be understood, however, that it may also be embodied in household furniture, such as a cabinet, desk, console or table, and that it is usable for machines or devices, such as record players and tape recorders, other than sewing machines. In the present example, cabinet 10 has a front wall 12, rear wall 14, side walls 16 and 18 and folding legs 20. Cabinet 19 also has a door 22 pivoted to the front wall and a bottom wall 24 having a cutout 26 to provide knee-access to the control arm 28of a rheostat 30 for controlling the speed of the sewing machine as described below. The top 32 of cabinet 10 has a rectangular aperture 34 in which the invertable machine support 48 is accommodated. I

Referring particularly to FIGS. 3-7, inclusive, there are affixed beneath cabinet top 32 along the front and rear edges of aperture 34 a pair of rails 36 and 38 each having half-round cut-outs 40 which, in cooperation with brackets 42, constitute trunnions for holding tubular stub shafts 44 and 45 which pivotally support the invertable machine support 48.

Invertable machine support 48 is essentially an oblong shallow box having a front side 50, rear side 52, ends 54 and 56, a top wall 58 and a rear Wall 60 all rigidly joined together by conventional cabinetry. Where, as illustrated, the invention is embodied in a portable cabinet, the top wall 58 is preferably provided with a handle 62, and where, as illustrated, the invention is adapted to house a sewing machine, the bottom Wall 60 is provided with a cut-out 64 contoured to receive the base 66 of an electrically-powered sewing machine 68 whose head 70 projects above base 66 and whose underneath mechanism 72 lies below base 66 within the confines of the invertabie support 48. The rear edge of the machine base 66 is connected to the rear side 52 of invertabie support 48 by conventional pivots and overlying the front corners of base 62 are conventional hold-downs '74.

The inner ends of hollow stub shafts 44, 45 are rotatably supported in bores 76 through the front and rear sides 50, 52 of invertable support 48, and affixed to the inner side of top wall 58 is a plug-in receptacle 78 whose leadin cord 82 passes rearwardly outward through tubular stub shaft 44 and the hold 46 in the rear wall 14 of cabinet 10. A double-wire 82 runs from receptacle '78 through tubular stub shaft 45 to rheostat 3% it being understood that by suitable conventional circuitry, rheostat 30 is in series with one side of the electrical circuit to which the power supply line 84 for the electric motor of the sewing machine is connected via receptacle 78. As shown in FIG. 7, a conventional latch 86 is provided for maintaining support 48 either in the position shown in FIG. 1 or in FIG. 2. Striker surfaces 87 are provided adjacent the upper and lower rear corners of rear wall 52 for camming latch 86 open as support 48 approaches one extreme position or the other.

On the exterior of the front side of invertable support 48 is secured a bearing plate 8% having an aperture through which stub shaft 45 passes and a forwardly projecting arm 96 to which the free end of a tension spring S 2 is connected. The fixed end of spring 92 is anchored to a book 94 which, as will be apparent from PEG. 9, is below the pivotal axis p.a. of invertable support 4-8, preferably at about 2230 along the arc of movement of arm 90 as the latter swings with support 48 from the position in which the machine 68 is upright (FIG. 2) to the position in which it is inverted (FIG. 1). As will be apparent from FIG. 8, arm as extends forwardly beyond rail 38 and the free end of spring 92 is attached around its forward end so that the spring does not interfere with support 48 or rail 38 at any point in the 180 swing of the free end thereof. Notches 96 in the underside of rail 38 on opposite sides of the pivotal axis p.a. accommodate arm 90 in its extreme positions, and the surfaces on the inner sides of notches 8 constitute stops which arm $6 engages for preventing the swinging movement of support 48 beyond 0 in one direction and 180 in the opposite direction.

The counterbalancing action of spring 92 is of great importance in the operation of the device. As will be seen by comparing FIGS. 9 and 10, during the first swinging movements of support 48 from the position in which machine 63 is upright up to about 30, spring 92 helps slightly, although the pulling effect is not great because the leverage exerted via arm 94} is not great. Then, as arm 90 swings beyond 2230 to about the spring which is under stretch at the 2230 point, is stretched back to its length at the 0 position. During this phase of movement, the weight and leverage of the machine start to become effective to the extent that the machine and its support, if not manually constrained, would swing violently downward were it not for the ever-increasing spring tension. After the machine passes a point at which the force applied by the spring balances the opposing force applied by the machine, an affirmative force must manually be applied to the support in order to swing the machine to its fully inverted position of FIGS. 1 and 4. However, in the final movements of the support from about 15730 to 180, very little further stretching of the spring occurs while, on the other hand, arm 90 approaches the point (which. it never quite reaches) at which it would be aligned with the pivotal axis pa. of the support and the point of anchorage 4 of the spring so that the resultant force applied by the spring rapidly diminishes as the leverage decreases. The net result, in actual practice, is that the final inverting movement of the support seem to require less manual force than the immediately' preceding ones, although the counterbalance is 4 such that very little effort is needed to swing the machine and its support from either extreme to the other.

It will be understood that the point of anchorage of the spring may be adjusted upwardly or downwardly so long as it is plus or minus a few degrees from 2230 as measured counterclockwise from the starting point of arm t) when the support is such that the machine is upright. Likewise, spring 92 will be selected as to length and strength to match the Weight and height of the par ticular machine to be mounted on support 48, the proper spring strength being easily determined empirically.

The closed ends 54, 56 of support 48 have proved to be a great safety feature in guarding against the catching of ones hands between the edges of top 32 and support 48 as the latter approaches its extreme positions.

The invention is not limited to the precise structure disclosed and illustrated herein, but is intended to cover all substitutions, modifications and equivalents within the scope of the following claims.

I claim:

l. A cabinet having a top with an oblong opening herein, a pair of rails affixed beneath the underside of said top adjacent the opposed long edges of the opening, coaxial trunnions on the undersides of said rails midway of the long sides of said opening, there being a space between that long side of one of said rails which lies remote from said opening and the adjacent wall of said cabinet, an invertable machine support disposed in said opening comprising an oblong box of a length and width slightly less, respectively, than the length and width of the opening, said box having elongate opposed side walls, end walls, a top wall and a bottom wall, means on said bottom wall for mounting a machine thereon, stub shafts pivotally supporting the side walls of said box midway between the ends thereof in said trunnions, an arm extending outwardly from that side wall of the box which lies adjacent said one rail, said arm extending transversely of the last-named rail and having a free end extending beyond that side of the last-named rail which lies remote from said opening, and a tension spring having a fixed end anchored to said cabinet at a point below the axis of said trunnions, said point being in a vertical plane which passes through said space and being spaced from said axis in the longitudinal direction of said opening, the free end of said spring being attached to the free end of said arm.

2. A cabinet having a top with an oblong opening therein, a pair of rails affixed beneath the underside of said top adjacent the opposed long edges of the opening, coaxial trunnions on the undersides of said rails midway of the long sides of said opening, there being a space between that long side of one of said rails which lies remote from said opening and the adjacent wall of sad cabinet, an invertable machine support disposed in said opening comprising an oblong box of a length and width slightly less, respectively, than the length and width of the opening, said box having elongate opposed side walls, end walls, a top wall and a bottom wall, stub shafts pivotally supporting the side walls of said box midway between the ends and the top and bottom walls thereof in said trunnions whereby said box may be rotated from a first position in which the bottom wall of the box is upwardly disposed and a second position from the first position in which the top wall of the box is upwardly disposed, means on said bottom wall for supporting a machine thereon, an arm extending outwardly from that side wall of the box which lies adjacent said one rail, said arm extending transversely of the last-named rail and having a free end extending beyond that side of the last-named rail which lies remote from said opening, first and second stop surface means on the underside of the last-narned rail on respectively opposite sides of the trunnion thereon, said arm, in the first position of said box engaging the first stop surface means and said arm, in the second position of the box, engaging the second stop surface means, whereby the rotation of said box is limited to said 180", and a tension spring having a free end connected to the free end of said arm and a fixed end anchored to said cabinet at a point disposed below the axis of the last-named trunnion on the same side thereof as the first stop surface means and also disposed in a vertical plane passing through said space.

3. The combination claimed in claim 2, the point of anchorage of the fixed end of the spring being on an arc of the radius of the axis of the last-named trunnion between 0 and 45 wherein said arm, in the first position of said box, is at 0 on an arc of the same radius.

4. The combination claimed in claim 3, the means on said bottom wall being adapted to support a sewing machine and including a cut-out in said bottom wall for accommodating the base of the sewing machine.

5. In the combination claimed in claim 4, said stub shafts being hollow, a rheostat afiixed on said cabinet, an electrical power supply line extending into the inte- References Cited by the Examiner UNITED STATES PATENTS 961,525 6/1910 Baltzley 31222 2,194,333 3/1940 Thompson 312-22 2,528,935 11/1950 Williams 312-30 X FOREIGN PATENTS 462,535 3/1951 Italy.

FRANK B. SHERRY, Primary Examiner.

J, L. KOHNEN, Assistant Examiner. 

1. A CABINET HAVING A TOP WITH AN OBLONG OPENING THEREIN, A PAIR OF RAILS AFFIXED BENEATH THE UNDERSIDE OF SAID TOP ADJACENT THE OPPOSED LONG EDGES OF THE OPENING, COAXIAL TRUNNIONS ON THE UNDERSIDES OF SAID RAILS MIDWAY OF THE LONG SIDES OF SAID OPENING, THERE BEING A SPACE BETWEEN THAT LONG SIDE OF ONE OF SAID RAILS WHICH LIES REMOTE FROM SAID OPENING AND THE ADJACENT WALL OF SAID CABINET, AN INVERTABLE MACHINE SUPPORT DISPOSED IN SAID OPENING COMPRISING AN OBLONG BOX OF A LENGTH AND WIDTH SLIGHTLY LESS, RESPECTIVELY, THAN THE LENGTH AND WIDTH OF THE OPENING, SAID BOX HAVING ELONGATE OPPOSED SIDE WALLS, END WALLS, A TOP WALL AND A BOTTOM WALL, MEANS ON SAID BOTTOM WALL FOR MOUNTING A MACHINE THEREON, STUB SHAFTS PIVOTALLY SUPPORTING THE SIDE WALLS OF SAID BOX MIDWAY BETWEEN THE ENDS THEREOF IN SAID TRUNNIONS, AN ARM EXTENDING OUTWARDLY FROM THAT SIDE WALL OF THE BOX WHICH LIES ADJACENT SAID ONE RAIL, SAID ARM EXTENDING TRANSVERSELY OF THE LAST-NAMED RAIL AND HAVING A FREE END EXTENDING BEYOND THAT SIDE OF THE LAST-NAMED RAIL WHICH LIES REMOTE FROM SAID OPENING, AND A TENSION SPRING HAVING A FIXED END ANCHORED TO SAID CABINET AT A POINT BELOW THE AXIS OF SAID TRUNNIONS, SAID POINT BEING IN A VERTICAL PLANE WHICH PASSES THROUGH SAID SPACE AND BEING SPACED FROM SAID AXIS IN THE LONGITUDINAL DIRECTION OF SAID OPENING, THE FREE END OF SAID SPRING BEING ATTACHED TO THE FREE END OF SAID ARM. 